A current sensor circuit can include one or more circuit components arranged to detect a current and provide a corresponding output signal, such as an output voltage signal. In an example, a current sensor circuit can be configured to provide an output voltage signal that is proportional to a detected or measured current signal. Current sensor circuits can be optimized to detect different ranges of current signal magnitudes or frequencies, or to operate under various environmental conditions.
An example of a current sensor can include a resistor configured as a current-to-voltage converter. A current I through a resistor R produces a voltage V according to Ohm's law, V=IR. The resistor can thus provide a substantially linear voltage response to a current signal over a particular operating range. A current sensor that includes a resistor to provide a current-to-voltage conversion can generally be inexpensive, accurate, and can be configured to measure DC or AC current signals. However, resistor-based current sensors can consume a significant amount of power, and can introduce unwanted resistance in the circuit path.